static <A, B> void scorePreciseRecognizer(Best<F1<A, B>> best, F1<A, B> recognizer, LPair<A, B> trainingList) {
  new Scorer scorer;
  for (Pair<A, B> p : trainingList)
    scorer.add(recognizer.get(p.a) == p.b);
  best.putAndPrintIfNewBest(recognizer, scorer!);
}